Grinding machine



March 12, 1940. R. McMILLEN GRINDING MACHINE Filed Aug. 24, 19158 2Sheets-Sheet 1 March 12, 1940. R; McMlLLEN ,192,981

GRINDING MACHINE Filed Aug. 24, 1938 2 Sheets-Sheet 2 Patented Mar. 12,1940 UNITED STATES 2.19am j TENT orrice 7 Claims.

This invention relates to grinding machines for grinding cuttinginstruments, particularly shears or scissors. It has for its principalobjects to provide a simple, strong, economical and 5 easily operablemachine that will accommodate sheas having beveled cutting edges ofvarious angles and that will provide for properly positioning and firmlyholding the shears in the machine. The invention consists in the shearsgrinder or sharpener and in the construction,

combinations and arrangements of parts hereinafter described andclaimed.

In the accompanying drawings, wherein like reference numerals refer tolike parts wherever 15 they occur,

Fig. l is a plan view of a shears sharpening machine embodying myinvention;

Fig. 2 is a front elevation thereof; Fig. 3 is a left-hand end view ofthe machine; Fig. 4 is a right-hand end View of the machine; Fig. 5 is avertical longitudinal section on the line 5-5 in Fig. 1;

Figs. 6, '7, 8 and 9 are enlarged fragmentary cross-sections on the line6-6, 1'|, 8-8 and cs-9, respectively, in Fig. 2; and

Fig. 10 is a rear View of the shears supporting carriage.

My shears sharpening or grinding machine comprises a base I provided atone end with a housing 2 containing intermeshing driving and drivengears 3 and 4 fixed to vertically spaced horizontally disposed drivingand driven shafts 5 and 6, respectively, journaled in the end walls ofsaid housing. The driving shaft 5 is rotated npreferably by means of acrank l fixed thereto clear of the adjacent end of the base I; and thedriven shaft 6 has a grinding wheel 8 of carborundum or other suitablematerial fixed thereto exteriorly of said housing. a, The shears thatare to be sharpened comprise 40 two blades 9 having handles and beveledcutting edges II and pivoted together intermediate their ends by a pivotscrew I2. The shears are mounted in a carriage A with the cutting edgeof the blade that is to be sharpened disposed parallel to the axis ofthe grinding wheel a and in position to engage the peripheral surface ofsaid wheel and with the other blade disposed crosswise of the grindingwheel axis. The shears .supporting carriage A is mounted for sliding 50movement longitudinally of the grinding wheel axis on a rod l4, one endof which rests in an opening provided therefor in one end of ahorizontal bar or bracket l that is disposed crosswise of the grindingwheel axis and is supported by a post or upright I6 fixed to the base iat the left-hand end thereof. The bar I5 is provided with an elongatedslot l8 and is clamped to the post it by means of a screw l9 having athumb nut Zll, whereby said bar and the rod M 6 carried thereby may beadjusted transversely of the grinding wheel axis. The opposite end ofthe carriage supporting rod M is supported in a horizontal bracket 2!that is secured to the adjacent end face of the gear housing 2 by meansof a screw 22, which passes through an elongated notch or slot 23 insaid bracket and registering holes provided therefor in the end walls ofsaid housing and is provided with a thumb nut 24 for clamping saidbracket to said l housing in its desired position of adjustmenttransversely of the grinding wheel axis. This bracket limits themovement of the carriage A in the direction of the grinding wheel,movement of said carriage in the opposite direction being limited by acollar 25 that is sleeved on the rod l4 and is held in the desiredposition of its sliding movement by means of a set screw 26.

The shears supporting carriage A. comprises two upright end sections orplates El, 28 that 25" scribed. The shank of the blade that is to be zsharpened is clamped in the groove 3! by means of a suitable thumb screw32; and the shank of the other blade is also clamped in said groovepreferably by means of a separate thumb screw 33. The rear end of theenlarged upper end 30 A of the end plate 2'! of the carriage is providedabove and below the groove M with alined notches 3 having enlarged innerend portions in which is centered the pivot screw l2 of the shears. Theplate 28 at the right-hand end of the carriage is also provided with anenlarged upper end portion 35 having a groove 36 in its rear end adaptedto receive the end portion of the blade that is to be sharpened.Movement of this portion of the blade, due to the pressure thereof,against the grinding wheel is prevented by means of a screw 31 which isthreaded through the upper end 35 of the plate 28 into the groove 36 inabutting relation to the rear edge of the blade, this screw being heldin the desired 5 position of adjustment by means of a coiled spring 38,which is sleeved thereon between the head thereof and the front face ofsaid upper end of said plate.

The end plates 21, 28 of the slidable shears sup-porting carriage A areeach provided at their lower ends with a series of notches 39 adapted tostraddle the carriage supporting rod. By means of these notches, thebeveled edge of the blade that is to be sharpened may be positioned atthe desired angle to the grinding wheel. This angle may also be variedby adjusting the carriage rod supporting brackets 15 and 2| transverselyof the grinding wheel axis.

In operation, the shears that are to be sharpened are clamped in thecarriage A in the manner shown and hereinbefore described. The carriageis then placed on the supporting rod M by engaging the correspondingnotch of each end plate of the carriage with said rod, the particularnotches that are placed in engagement with the rod depending on thebevel that is desired for the cutting edge or" the blade. The grindingwheel is then rotated while the carriage is slid back and forth alongthe supporting rod to bring the entire length of the cutting edge of theblade into engagement with the grinding wheel. The blade is preventedfrom sliding off the grinding wheel by means of the adjustable collar25, while the bracket 21 serves to prevent the other blade from engagingthe end face of the grinding wheel.

The hereinbefore described shears sharpener has several importantadvantages. It enables the shears to be readily clamped in properposition on the supporting carriage and it enables an unskilled operatorto obtain any desired bevel on the cutting edge with a minimumexpenditure of time and effort. By engaging the same notches with thesupporting rod each time the shears are sharpened, the same beveledcutting edge may be retained. The notches 3 5 serve as a guide forproperly positioning the shears in the carriage; and they also provideclearance for both ends of the pivot screw i2.

Obviously, the hereinbefore described arrangement admits of considerablemodification without departing from the invention. Therefore, I do notwish to be limited to the precise construction shown and described.

What I claim is:

1. A sharpener for tools having beveled cutting edges comprising arotatable grinding wheel, a single rod disposed alongside of said wheelparallel to the axis thereof, a quick detachable tool supportingcarriage supported on said rod for sliding movement thereon and forswinging movement thereon transversely of said axis, and means wherebysaid carriage may be supported on said rod at any one of a plurality ofdifierent portions of the carriage to thereby vary the angle of the toolwith respect to said grinding wheel.

2. A sharpener for bevel edged tools comprising a rotatable grindingwheel, a single rod disposed alongside of said wheel parallel to theaxis thereof, and a carriage having a tool supporting upper end portionand a series of notches in its lower end spacedapart crosswiseof saidrod and each adapted to be selectively engaged with said rod to vary theangle at which the tool is held to said grinding wheel.

3. A sharpener for shears having beveled cutting edges comprising arotatable grinding wheel, a carriage mounted for movement in a directionparallel to the grinding wheel axis, means for mounting said shears insaid carriage with the cutting edge of one blade disposed parallel tothe grinding wheel axis and means for adjusting said carriage to bringthe beveled cutting edge of said blade tangent to the peripheral surfaceof said grinding wheel, said means comprising a single rod for slida-blysupporting said carriage and a series of notches formed in said carriageand spaced apart crosswise of said rod for selective engagementtherewith.

4. A sharpener for shears having beveled cutting edges comprising arotatable grinding wheel, a carriage mounted for movement in a directionparallel to the grinding wheel axis, means for mounting said shears insaid carriage with the cutting edge of one blade disposed parallel tothe grinding wheel axis, and means for adjusting said carriage to bringthe beveled cutting edge of said blade tangent to the peripheral surfaceof said grinding wheel, said means comprising a single rod for slidablysupporting said carriage and a series of notches formed in said carriageand spaced-apart crosswise of said rod for selective rocking engagementtherewith, and adjustable means on said rod for limiting the slidingmovement of the carriage away from said grinding wheel.

5. A shears sharpener comprising a rotatable grinding wheel, a shearssupporting carriage, a a

said carriage having a series of notches formed therein and spaced apartcrosswises of said rod for selective engagement therewith, said carriagebeing provided in its grinding wheel opposing side with a groove adaptedto receive both blades of said shears, means for clamping said blades insaid groove, said carriage having a second groove disposed in alinementwith said first mentioned groove and adapted to receive the blade thatis to be sharpened, and an adjustable abutment in said second groove forthe rear edge of said blade.

7. A quick detachable shears supporting carriage for a shears sharpenerof the kind described,

said carriage having a series of notches formed in the lower end thereofadapted for selective engagement with a single support therefor, the

